Bipolar I disorder
Bipolar I disorder is a chronic mood disorder defined by at least one manic episode lasting a week or requiring hospitalization, with three or more DIG FAST symptoms causing marked impairment. Diagnosis is clinical after substances and medical mimics are excluded. Acute mania is treated with lithium or valproate, often with an atypical antipsychotic, and most patients need lifelong mood-stabilizer maintenance.
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What this article covers
- Overview
Definition: a chronic, recurrent mood disorder defined by at least one manic episode; a depressive episode is not required, and psychotic features occur only in bipolar I, not the hypomania-based subtype.
- Epidemiology
Prevalence: lifetime prevalence is about 1% to 3%, occurring in men and women at similar rates.
- Risk factors
Family history: a first-degree relative with bipolar disorder or another mood disorder is linked to higher risk.
- Pathophysiology
Episodic mood dysregulation: grouped with the mood disorders, defined by disturbances in mood, cognition, and vegetative function that impair functioning; no single unifying mechanism is specified.
- Clinical features
Manic episode, the defining event: a distinct period of abnormally and persistently elevated, expansive, or irritable mood with heightened activity or energy, lasting at least 1 week, or any duration if hospitalization is required.
- Differential diagnosis
Bipolar II disorder: a hypomanic episode (at least 4 days, without marked impairment, hospitalization, or psychosis) plus a major depressive episode, but never a full manic episode.
- Diagnosis
The diagnosis is clinical: confirmed when a patient meets criteria for at least one manic episode not better explained by a substance or another medical condition; no laboratory test establishes it.
- Management
Stabilize first if agitated, psychotic, or a danger to self or others: admit to a psychiatric unit, involuntarily if required, and treat agitation before finalizing a maintenance plan.
- Complications
Suicide: up to 10% to 15% of patients with bipolar disorder complete suicide over their lifetime, the highest risk among the major mood disorders.
- Prognosis
Recurrent, episodic course: patients typically return to baseline between episodes, but episodes become more frequent as the illness ages.
- Prevention
Screen before prescribing an antidepressant: ask every depressed patient about prior manic or hypomanic symptoms and family history of mood disorders; antidepressant monotherapy in unrecognized bipolar disorder can precipitate mania.
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Related articles
- Bipolar II disorder
Bipolar II disorder requires at least one hypomanic episode (elevated or irritable mood for 4 or more consecutive days without marked impairment, psychosis, or hospitalization) plus at least one major depressive episode, and no lifetime history of a full manic episode; first-line treatment is lithium with careful avoidance of unopposed antidepressants.
- Cyclothymic disorder
Cyclothymic disorder is a chronic bipolar-spectrum illness with numerous hypomanic-range and depressive-range periods that never meet full episode criteria for at least 2 years (1 year in children). Diagnosis is clinical; first-line treatment is cognitive behavioral therapy (CBT), with divalproex sodium started when functioning is impaired.
- Major depressive disorder
Major depressive disorder is a mood disorder defined by 5 or more of 9 major depressive episode symptoms, including depressed mood or anhedonia, present nearly every day for at least 2 weeks and causing significant functional impairment. Diagnosis is clinical, screened with the Patient Health Questionnaire. First-line treatment is cognitive behavioral therapy, a selective serotonin reuptake inhibitor (SSRI) such as sertraline, or both, escalating to augmentation, esketamine, or electroconvulsive therapy for refractory or acutely suicidal presentations.
- Mood stabilizers for bipolar disorder
Valproate/divalproex, lamotrigine, carbamazepine, oxcarbazepine, and second-generation antipsychotics are the mood stabilizers used for bipolar disorder when lithium is ineffective, poorly tolerated, or contraindicated. Valproate treats acute mania, mixed episodes, and rapid cycling with an oral loading dose; lamotrigine, titrated slowly to limit serious rash, treats bipolar depression and maintenance but not acute mania; carbamazepine is second-line, limited by agranulocytosis.
- Borderline personality disorder
Borderline personality disorder is a cluster B personality disorder defined by 5 or more of 9 DSM-5 criteria spanning instability of relationships, self-image, and affect, marked impulsivity, and recurrent self-injury or suicidality; dialectical behavior therapy is the first-line treatment, with pharmacotherapy reserved as a secondary, symptom-targeted adjunct.